Michiko Konda, Truth Seeker

Whenever a source an opponent controls deals damage to you, that player sacrifices a permanent.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Queza, Augur of Agonies

Whenever you draw a card, target opponent loses 1 life and you gain 1 life.

Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

The Mouth of Sauron

When The Mouth of Sauron enters, target player mills three cards. Then amass Orcs X, where X is the number of instant and sorcery cards in that player's graveyard. (Put X +1/+1 counters on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Obzedat, Ghost Council

When Obzedat, Ghost Council enters, target opponent loses 2 life and you gain 2 life.
At the beginning of your end step, you may exile Obzedat. If you do, return it to the battlefield under its owner's control at the beginning of your next upkeep. It gains haste.

Gríma, Saruman's Footman

Gríma, Saruman's Footman can't be blocked.
Whenever Gríma deals combat damage to a player, that player exiles cards from the top of their library until they exile an instant or sorcery card. You may cast that card without paying its mana cost. Then that player puts the exiled cards that weren't cast this way on the bottom of their library in a random order.

Ledger Shredder

Flying
Whenever a player casts their second spell each turn, Ledger Shredder connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Sram, Senior Edificer

Whenever you cast an Aura, Equipment, or Vehicle spell, draw a card.

Atris, Oracle of Half-Truths

Menace
When Atris, Oracle of Half-Truths enters, target opponent looks at the top three cards of your library and separates them into a face-down pile and a face-up pile. Put one pile into your hand and the other into your graveyard.

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Glóin, Dwarf Emissary

Whenever you cast a historic spell, create a Treasure token. This ability triggers only once each turn. (Artifacts, legendaries, and Sagas are historic.)
{T}, Sacrifice a Treasure: Goad target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard Eiganjo, Seat of the Empire: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Kambal, Consul of Allocation

Whenever an opponent casts a noncreature spell, that player loses 2 life and you gain 2 life.

Hurkyl, Master Wizard

At the beginning of your end step, if you've cast a noncreature spell this turn, reveal the top five cards of your library. For each card type among noncreature spells you've cast this turn, you may put a card of that type from among the revealed cards into your hand. Put the rest on the bottom of your library in a random order.

Minister of Inquiries

When Minister of Inquiries enters, you get {E}{E} (two energy counters).
{T}, Pay {E}: Target player mills three cards.

Thrumming Stone

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Serum Powder

{T}: Add {C}.
Any time you could mulligan and Serum Powder is in your hand, you may exile all the cards from your hand, then draw that many cards. (You can do this in addition to taking mulligans.)

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
Raffine's Tower enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Snow-Covered Island

Hauken's Insight

At the beginning of your upkeep, exile the top card of your library face down. You may look at that card for as long as it remains exiled.
Once during each of your turns, you may play a land or cast a spell from among the cards exiled with this permanent without paying its mana cost.

Jacob Hauken, Inspector

{T}: Draw a card, then exile a card from your hand face down. You may look at that card for as long as it remains exiled. You may pay {4}{U}{U}. If you do, transform Jacob Hauken, Inspector.

Jacob Hauken, Inspector // Hauken's Insight

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Grand Arbiter Augustin IV

White spells you cast cost {1} less to cast.
Blue spells you cast cost {1} less to cast.
Spells your opponents cast cost {1} more to cast.

Imperial Recruiter

When Imperial Recruiter enters, search your library for a creature card with power 2 or less, reveal it, put it into your hand, then shuffle.

Masako the Humorless

Flash
Tapped creatures you control can block as though they were untapped.

Rivendell

Rivendell enters tapped unless you control a legendary creature.
{T}: Add {U}.
{1}{U}, {T}: Scry 2. Activate only if you control a legendary creature.

Jwari Ruins

Jwari Disruption

Counter target spell unless its controller pays {1}.

Jwari Disruption // Jwari Ruins

Kongming, "Sleeping Dragon"

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.

Cunning Advisor

{T}: Target opponent discards a card. Activate only during your turn, before attackers are declared.

Loyal Retainers

Sacrifice Loyal Retainers: Return target legendary creature card from your graveyard to the battlefield. Activate only during your turn, before attackers are declared.

Light-Paws, Emperor's Voice

Whenever an Aura you control enters, if you cast it, you may search your library for an Aura card with mana value less than or equal to that Aura and with a different name than each Aura you control, put that card onto the battlefield attached to Light-Paws, Emperor's Voice, then shuffle.

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Corrupt Court Official

When Corrupt Court Official enters, target opponent discards a card.

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Gregor, Shrewd Magistrate

Skulk (This creature can't be blocked by creatures with greater power.)
Whenever Gregor, Shrewd Magistrate deals combat damage to a player, draw cards equal to its power.